All work environments have different expectations for an employee’s work schedule.  A long term employee could be well adjusted to his/her schedule when they are told by their employer that it is about to change. Is an employer legally allowed to change the work schedule and what are the implications?
Question:

 Can an employer change an employee’s work schedule?  In my case, I was working 7:00am to 4:00 pm, Monday to Friday for the last 7 years and now my company has told me to work some evenings and some weekends.  Can I refuse?

Answer: 

An employer is permitted to set hours of work and to make certain limited changes to your hours of work.  Work environments are not static and employers can require employees to work outside of their regular working hours.  However, if the employer makes a significant change to your work schedule without your agreement, such as requiring you to regularly work evenings and weekends, this may trigger a constructive dismissal.  You can refuse to accept the change in hours, in which case the employer may terminate your employment.  In these circumstances, you are entitled to demand a severance package.  Even if the employer does not formally terminate your employment, you can resign from your job and demand a severance package as though your employment had been terminated.    Ultimately, the employee bears the onus of establishing that s/he has been constructively dismissed from their job.  There is no specific formula in terms of what type of change in working hours triggers a constructive dismissal.   Each case is decided on its own facts and in particular, decisions are based on whether the employee has other obligations or circumstances that may make the change in work hours particularly onerous.